FMWNTs/GO/MnO2 nanocomposites as additives in a membrane for the removal of crystal violet

Abstract

In this work, the performance of a mixed matrix membrane in the removal of crystal violet from aqueous solutions is reported. This membrane was fabricated by adding a nanocomposite (fMWNTs/GO/MnO2 NC) synthesized with functionalized multi-walled carbon nanotubes, graphene oxide, and manganese dioxide nanoparticles, to polysulfone. Details pertaining to the preparation and characterization of the membrane, evaluation of its performance in the removal of crystal violet, and antifouling properties of the membrane are reported in this paper. The membranes were fabricated by embedding varying concentrations of fMWNTs/GO/MnO2 NC (from 0 to 0.3wt%) in the Psf matrix. Incorporation of fMWNTs/GO/ MnO2 NC was found to enhance hydrophilicity, equilibrium water content, porosity, mean pore radius, pure water permeability and antifouling properties of the membrane. Analyses of surface morphology of the fabricated membranes revealed the presence of macro-voids in the matrix of the membrane after addition of fMWNTs/GO/MnO2 NC, resulting in an increase in pure water flux and permeability. It was observed that 0.1wt% is the optimum concentration of fMWNTs/GO/ MnO2 NC in the Psf matrix since the membrane exhibited maximum hydrophilicity, equilibrium water content, porosity, pure water permeability and dye rejection at this concentration. Also, it was observed that the polysulfone membrane exhibited enhanced antifouling properties at this concentration of the nanocomposite.